负弯矩区组合扁梁的受力性能分析

Structural Behavior of Steel-Concrete Composite Slim Beam in the Negative Moment Region

目的分析负弯矩区组合扁梁的受力性能,计算其弹性刚度和极限承载力,验证所取得的理论结果.方法运用弹塑性力学知识,通过平截面假定和换算截面法,对负弯矩区组合扁梁的受力性能进行了理论分析.结果提出简化的计算模型,推导了弹性刚度和极限承载力公式;并运用大型有限元软件Ansys进行数值模拟.将两者的结果进行了比较,吻合良好.结论研究工作表明笔者所提的简化理论模型及其刚度、强度公式较好地分析了负弯矩区组合扁梁的受力性能,结果合理,可为实际工程设计提供借鉴和参考.

The structural behavior of composite slim beam in the negative moment region is the basis of the structural design. The concrete in the negative moment region may crack, and researches so far on the loading capacity of this type of beam are not adequate. Thus, the structural design nowadays largely depends on experiences, which greatly limits its application. In this paper, the behavior of a cantilever composite slim beam has been investigated by using theoretical analysis. At the same time, a simplified model is gained by the beam theory and the equivalent-section method in the elastic-plastic mechanics, so do the equations of the elastic stiffness and limited capacity. Numerical simulations have also been carried out by Ansys, a general FEA package. The analysis results agree well with each other. Consequently, this method is effective enough to investigate the composite slim beams and this simplified model can be used in the engineering design.